Ductile iron – also referred to as spheroidal or nodular iron – is actually a group of irons that exhibit high strength, flexibility, durability and elasticity due to their unique microstructure. Cast ductile iron normally contains over 3 percent carbon; it can be bent, twisted or deformed without fracturing. Its mechanical properties are similar to steel, and far exceed those of standard cast irons.

Ductile iron castings are solid metal objects that result from molten ductile iron being poured into voids in a mold. The ductile iron subsequently cools and solidifies in the shape of the void it occupies.